Minimum slope of a metal tile roof: the best option. Minimum roof slope: how to correctly calculate Roof with a small angle of inclination

On our planet you can count thousands of varieties of roofs, dictated by various architectural traditions. At present, architects have completely changed the idea of suburban construction. Now shed roofs have become an ideal for combining many of their designs with landscape design. In this article we will talk about what the angle of inclination should be one pitched roof so that its functionality meets the requirements of the snowiest regions of Russia.

Calculation of permanent and dynamic loads

When determining the slope of a pitched roof, first calculate the loads that may fall on it. They can be permanent or dynamic. Constants include the mass of the roofing covering, chimneys, antennas, dishes, and so on - since they are always an integral part of the roof.

Dynamic or variable loads include those that occur with some frequency. These include: snow, hail, the presence of a person with all repair tools and materials. To this we can also add the wind, which can tear off pitched roofs due to the windage of the roofing covering.

Loads caused by snow precipitation

If we imagine that the angle of the pitched roof will be equal to 30º, in winter time For each square meter of coverage, a force of 50 kg will be applied. It's the same as on every square meter One person at a time will be seated.

If you make a slope of more than 45º, then, most likely, the snow simply will not be able to stay on such a roof (much, of course, depends on the roughness roofing material). But for regions of Russia located on middle lane with moderate snowfalls, a pitched roof slope of 30-35 degrees is sufficient.

Acceptable minimum slope canopy for independent snow removal is 10º. The maximum slope is 60º - it is impractical to build a roof with a steeper angle.

Owners of pitched roofs with insufficient slope often take up a shovel. Only the coverage area can be saved, since as it decreases, the chance of sagging of the roofing material also decreases.

Wind loads

Everything is different in windy areas - it is strictly forbidden to construct single-pitched roofs from corrugated sheets with large angles. For example, a shed roof with a 45-degree slope must resist wind forces that are 5 times greater than those that act on an 11-degree slope. Based on this, keep in mind that a pitched roof must be constructed in such a way that its low part is located towards the leeward side.

Mixed loads

Do not forget to additionally calculate for a pitched roof such indicators as the combination of short-term factors with negative ongoing loads. This refers to critical values ​​that can affect the rafter system. Many, oddly enough, quite often do not take this factor into account, guided by the fact that if the roof can withstand snow, then it will withstand any exposure to wind.

Imagine that several people will have to climb onto the roof in heavy snow under gusts of wind. Will it be able to withstand several people, snowfall and strong winds at the same time? At such moments, all sorts of unpleasant incidents happen.

Determining the minimum slope of a pitched roof

When deciding what slope a pitched roof should have, it is worth noting that there are quite wide boundaries: from 6 to 60 degrees. Everything is determined by the region in which it is planned to build the house. If you don’t want to suffer from tons of snow falling on your roof year after year, then build a roof with a steeper slope. And if you plan to protect yourself from the wind, then build a roof with a flatter slope. Much, of course, will depend on the aesthetic preferences of the owner.

Pitched roofs with a high slope

The higher the angle of such a roof, the less time it takes to drain water into the gutters. Neither leaves nor various debris will accumulate on it, which means the roofing material can last much longer. In addition, such a roof will look much more aesthetically pleasing in appearance, which will mean a lot to many owners.

Shed roofs with a slight slope

Naturally, from roofs with a slight slope, rain and melt water drains more slowly; as a result, it can begin to stagnate, ice will begin to get stuck in the drains, and dirt will also accumulate. Such roofs quickly become covered with moss and leaves stick to them. The worst thing is if the roofing material has a rough coating.

When determining what angle a pitched roof should have, it is necessary to provide such a structure so that precipitation and melt water do not linger on it, but roll off with ease. With a low slope, water will begin to collect in all the flaws in the roof. And over time, it will be able to penetrate inside the roof, causing many problems, such as dampness, damage to the insulation, and rusting of the metal components of the roof frame.

But in this case there is also positive side: at lower slope geometry interior rooms is getting closer to the “usual” cube. For many, it is easier to perceive, and at the same time it can be used with greater impact. This means that with a lower pitch, the roof will require more waterproofing to prevent water from entering the rafter system. Here you will need to purchase protective coatings, such as membranes, insulation in rolls or sheets.

With a minimum roof angle with one slope

Quite often, pitched roofs with a slope of only 3-5% are constructed as inversion roofs. This means that such a roof will be able to withstand additional increased loads: it is safe to walk on it, you can grow a garden on it, or even use it as a open terrace. It is worth noting that there is a certain angle at which a pitched roof can redirect the air flow, removing accumulated precipitation in the desired direction.

What angle of inclination should be in this or that case?

Based on their functionality, pitched roofs are divided into three main types: ventilated, unventilated and mixed. Each of them is worth considering in more detail.

Ventilated design

Closed structures are equipped with such roofs. The role of ventilation is played by vents and specially designated gaps between the layers of insulation, through which air carries droplets of moisture outside the insulation.

Without such ventilation, moisture will begin to accumulate inside the insulating material, causing it to become damp and deteriorate. After some time, everything will become unusable roofing pie. A ventilated pitched roof has a number of limitations. The angle of inclination of such a roof can only be in the range from 5 to 20%, otherwise air flows will not be able to circulate well enough through the vents.

Non-ventilated design

To understand what slope a shed roof should have, you need to consider a roof without ventilation. As a rule, such buildings are erected on highways and utility buildings. Often, such roofs have an angle ranging from 3 to 6%, however, there are no strict restrictions on the slope.

Such roofs, by and large, do not need ventilation, since the air masses in rooms where there are no walls or doors are wide open circulate quite well, carrying any water vapor out into the street. Although, in such buildings, moisture practically does not collect on its own.

Mixed design

Such roofs combine the characteristics of the two previous types of construction. In this case, the slope of the roof is given by thermal insulation. It turns out to be quite economical, but winter period You will need to clear the roof of snow quite often.

The design of such a pitched roof is somewhat different: in addition to corrugated sheeting, insulation is additionally laid in two layers and high-quality waterproofing is made.

In addition, the angle is determined by the type of connection of the rafters to the mauerlat or walls.

We calculate the exact slope of the slope

The slope of a shed roof is the angle of inclination of the rafters and roof slope in relation to the horizontal ceiling - calculated in degrees or percentages.

Deciding on the roofing covering

Different roofing materials have their own acceptable limits:

• corrugated sheeting – 8º-20º;
• seam covering - 18º-30º;
• slate - 20º-50º;
• soft type of roofing - 5º-20º;
• metal tiles - 30º-35º.

For smaller slopes you will need budget materials: roofing felt, corrugated sheets and similar ones.

Surprisingly, even for roofs with a low slope, today they produce the same roofing materials as for roofs with a slope of 30 degrees.

Which rafter system to choose

The type of fastening of the rafters to the walls is determined by the slope of the roof, as well as the loads that will fall on it.

Today there are the following types of rafters:

• Hanging. Most best option, if you want to get the most rigid connection, but it is not possible to install an additional stop under the side supports.

In other words, only external load-bearing walls are present, and there are no partitions. We can say that such a rafter system turns out to be very complex, so its production must be carried out with sufficient responsibility. Nuances arise due to long spans and the bursting force that puts pressure on the walls.

• Layered. In this case, the entire roof exerts pressure on at least three supports: two external walls and one located inside. The rafters should be as dense as possible, with a cross-section of at least 5x5 cm for the beams, and 5x15 cm for the rafter legs.
• Sliding. This design assumes that a ridge beam will serve as one of the supports under the rafters. And to connect it to the rafters, special metal fasteners are used - “slippers”. They enable the rafter system to move forward a very short distance in case of wall shrinkage, in order to avoid the appearance of cracks. This helps the roof to easily withstand even significant shrinkage of the frame, without causing damage.

Calculate the height of a roof with one slope

To determine the height of the roof being built, you can use one of three well-known methods:

• geometric;
• trigonometric;
• online calculator.

The most in a simple way, how to calculate the slope of a pitched roof, online calculators are considered. As a rule, they are configured to comply with SNiPs - “Load and Impact” TKP 45-5.05. However, it is worth considering that this method is best used only as an auxiliary one.

So we figured out how to determine the minimum slope of a pitched roof. We hope that you make the correct calculations and your roof will last longer than planned!

Any house is crowned with a roof - one of the main structures of the building that protects it interior spaces from rain and snow. One of the main criteria for any roof is the steepness of the slopes. Because flat roof is distributed mainly only in multi-storey residential and industrial construction, this issue is especially relevant for owners of private houses and cottages.

The amount of roofing material depends on the slope of the roof, so the choice of the slope angle and its preliminary calculations should be made before purchasing roofing material.

Let's consider how to determine the angle of inclination of a pitched roof and its connection with the design of the entire roofing structure.

In this article

What determines the steepness of a roof?

The angle of the roof directly affects its performance characteristics. In construction, there are 4 types of roofing structures:

• Steep with a slope of 45-60°;
• Sloping – 30-45°;
• Flat – 10-30°;
• Flat with a slope of less than 10°.

Determining this value depends on a number of factors:

• Exposure to wind. The wind exerts the greatest pressure on steep roofs, as they have the greatest windage due to their large surface area. When arranging such a structure, it is important to pay special attention to strength rafter system.

In areas with high wind loads, it is also dangerous to install flat and flat roofs: if the structure is weakly fastened, it may collapse. Thus, in areas with strong winds The recommended roof slope angle is in the range of 25-30°.

It is not necessary to equip a steep roof: a certain amount of snow that lingers on the roof in winter has useful property keep warm. However, it is important to calculate the load exerted by the snow cap on the structure in order to prevent it from collapsing.

• Roofing material. Each type of roof has its own limitations on the angle of inclination of the slopes. If you plan to use a specific roofing material, then it is important at the design stage to correlate the desired slope of the roof with its technical characteristics.
• Attic size. The angle of the roof directly affects the size of the room below it. The steeper the roof and the higher the ridge, the more spacious the attic and vice versa. When planning a room under the roof, we must not forget about the risks inevitably associated with a steep structure and its high cost compared to the construction of flatter roofs. A broken type can come to the rescue in this situation, which allows you to save the maximum volume for arranging the room, saving on the height of the ridge.

Minimum tilt angle

Such a concept as the minimum angle of roof inclination is related to the roofing material used. All roofs are provided with technical specifications, which, among other things, clearly indicate the slope limits for use. These rules cannot be violated, since in this case the roofing material will not retain its original functions and advantages.

Let's consider the main roofing coverings and the minimum angles for them:

• Piece roofing materials (slate, tiles) are laid on roofs with a slope of 22°. This indicator is due to the fact that in this case at the junctions roofing elements water does not accumulate and, accordingly, cannot seep under them;
• When working with rolled materials such as roofing felt, it is important to determine in advance the number of layers. If you plan to lay 2 layers, then the roof angle should be at least 15°; when laying 3 layers, this value can be reduced to 2-5°;
• The corrugated sheet is installed at a slope of 12°. A lower value will require treating all joints with sealant;
• Metal tiles spread at a value of 14°;
• Ondulin – from 6°;
• Soft tiles can be laid on a roof with a slope of 11° if there is a continuous sheathing;
• Membrane roofing materials are the only ones for which there is no minimum threshold. They can be successfully used on flat roofs.

Following the above rules is extremely important, since even a slight violation of them will result in the destruction of the roof and, possibly, damage to the rafter system.

Calculation of the angle of inclination

In addition to the minimum angle, there is such a thing as the optimal angle of inclination. With it, the roof is subjected to the minimum possible loads from wind, snow, etc. Let us give examples of such optimal values:

• In areas with frequent precipitation in the form of rain and snow, it is optimal to build a roof with a slope of 45-60°, as it gets rid of precipitation faster, which minimizes the load on the rafter system;
• If the roof is being erected in a windy region, then it would be good to place its angle of inclination in the range of 9-20°. It will not play the role of a sail, catching the passing wind, but it will not capsize due to its sharp gusts;
• In areas where both wind and snow occur regularly, average values ​​of 20-45° are used. This range can be called universal for pitched structures.

Independently calculating the angle of the slopes comes down to a simple geometric process, which is based on a triangle. Its legs are the height of the ridge and half the width of the house, the hypotenuse is one of the slopes. And the angle between the hypotenuse and the leg is the desired value of steepness.

The angle of the roof is directly related to the height of the ridge. There are two options for calculating these values:

• Known roof height. If there is a desire to arrange a spacious living room under the roof with an acceptable ceiling height, then the height of the ridge can be determined in advance. Having known two legs, it is easy to find out the size of the desired angle.

Let us accept the following notation:

• H – ridge height;
• L – width of half of the house;
• α is the desired angle.

Find the tangent of the desired angle using the formula:

tg α =H/L

We find out the value of the angle from the obtained value from a specialized table of tangents.

• Pre-determined tilt angle. If you want to use a specific roofing material or due to weather conditions in the region, the roof slope can be determined in advance. Based on its value, you can determine the height of the ridge of the house and check whether it is possible to create a living room under this roof. To arrange the premises, the height of the ridge must be at least 2.5 m.

We leave the conventions from the previous example and substitute the known quantities into the following equation:

H = L * tan α

Thus, the process of calculating the angle of inclination is much simpler and faster than analyzing all the aggregates to determine its optimal value for a particular region and building.

Due to the fact that a pitched roof rests on walls of different heights, the calculation of a given angle of inclination is carried out by simply raising one of the walls of the house.

We draw a perpendicular along the wall L d (the length of the wall of the house), originating at the point where the short wall ends and resting on the wall that has the maximum length.

If the length of the wall of the house L сд is equal to 10 meters, then in order to obtain an angle of inclination of 45 degrees, the length of the wall L bc should be equal to 14.08 meters.

Conclusion

In roof design, finding the optimal pitch angle is important. This parameter depends on a correct assessment of weather conditions, the choice of roofing material, and the desire to create living space. Its correct definition is the key to long and successful roof service in all weather conditions.

Roof of the house

A roof is a structural element of a building that is responsible for protecting it from external factors. It must successfully withstand precipitation in the form of rain, hail, snow, heavy winds and destructive hurricanes. The correct roof slope plays a big role in quickly removing water and snow from the roof. In combination with high-quality waterproofing, it provides excellent protection for the entire structure, including the interior.

Not only these indicators, but also its long-term operation and strength will depend on the correct slope of the roof. How to make the calculation correctly, what factors to take into account, how to calculate it for roofs with different coatings - all these questions will be discussed in this article.

About the factors influencing the calculation of the roof slope angle

Roofs, as already written on our website, have different shapes and the number of slopes. They come in one-, two- and four-slope types. The angle of the roof depends on the number of slopes on your house.

Construction work on installing the roof may be suspended if you do not decide in advance what material you are going to use for the finishing coating and what angle of inclination of the roof. It must be remembered that these two concepts are closely intertwined, since the type of roofing material proposed will be taken into account when calculating the angle of inclination of any pitched roof.

Let us dwell on the factors that are taken into account when calculating the angle of inclination of the roof.

For example, when choosing the angle of inclination of a pitched roof within 9-20 degrees, you will need to take into account factors such as

• finishing coating material;
• existing climatic conditions;
• functional purpose of the building.

In the case where the roof has two or more slopes, then not only the above factors and the area in which the house will be built will be taken into account. It will be necessary to take into account the purpose for which the attic space is being installed. If it is not intended for housing, but should be used to store temporarily unused things and objects, then you should not arrange a large room for these purposes (we are talking about the height of the ceiling). When the owners plan to turn the attic into a living space in the form of an attic, then the need arises to install a good roof with a significant slope.

In those regions where strong winds are not uncommon, the roof slope is minimal. Therefore, it is not subject to such strong wind influence. It is also not recommended to make roofs without a slope. Such coatings can be installed in regions with a large number of sunny days and a low probability of precipitation.

Wind resistance at high roof significantly more than at low. However, with a very small slope, there is a possibility that the wind could tear off the finish. It turns out that with very steep roofs there is the same danger as with roofs that do not have a slope at all. It is therefore recommended to choose the following roof slopes - in light winds it can range from 35 to 40 degrees, in strong winds the optimal roof slope angle is 15-25 degrees.

In areas where precipitation occurs in large quantities (we are talking about snowfall, hail and rain), the angle of inclination can be increased to 60 degrees. It is the most suitable because it allows you to minimize the load on the roof from snow cover, as well as melt water and large amounts of moisture during rain.

Taking into account all of the above, the roof inclination angle is calculated based on the range from 9 to 60 degrees. Designers, as a rule, make appropriate calculations and usually settle on values ​​that range from 20 degrees to 45.

Why is this roof angle attractive? The fact that you can use any roofing material - metal tiles, corrugated sheets, slate, etc. However, each finishing material has its own requirements, which are taken into account when constructing the roof structure.

1. The use of built-up materials is most suitable when the roof has a slope of 0-25%. When the slope is 0-10%, the material must be laid in three layers. If the angle of inclination is in the range of 10-25%, you can get by with one layer, but the material must have a sprinkle.
2. Roofs with a roof slope of up to 28% are covered with asbestos-cement corrugated sheets (slate).
3. Tiles are used when the roof has a slope of at least 33%.
4. The steel covering is laid on the roof with a slope angle of less than 29%.

Material consumption directly depends on the roof slope. The larger it is, the greater the consumption of finishing material. As a result, a flat roof in this regard will cost less than a roof with a 45-degree slope.

If you know the roof slope, then calculate the amount required material is not difficult. The same can be said about the height of the roof structure.

Let's look at each specific type of roofing.

Metal roofing

Compared to other roofing materials, metal tiles have considerable weight. Therefore, when constructing a roof structure using such a finishing coating, you should take into account all the nuances and try to build it so that it has a minimum roof slope angle.

This issue deserves special attention in areas with very strong winds. As you know, wind loads have a strong and negative impact on the roof. In this case, the calculation of the roof structure must be done especially carefully. When the angle of the roof is large, “swelling” of the roof may occur, which will lead to an increase in load, which will affect the entire structure. In turn, this can lead to premature failure of the roof.

Roofs that are covered with metal tiles must have a minimum slope angle of 22 degrees. Empirical data says that thanks to this indicator, the accumulation of moisture at the joints of the roofing is prevented. They are protected from unwanted seepage of water in the form of melted snow or rain.

Important! The minimum roof slope, when such a need exists, can be at least 14 degrees. If soft tiles are used as a covering, then the minimum value is reduced to 11 degrees. In this case, it would be correct to arrange additional continuous sheathing.

Corrugated roofing

It is known about corrugated sheeting that it occupies the place of one of the most popular roofing materials. Everyone knows its advantages in the form of low weight and ease of installation. Fastening profiled sheets to the roof is not difficult.

Important! It should be noted that when installing such a roof, the requirements for minimum angle the roof slope is more than 12 degrees (you should look at the manufacturers’ recommendations).

Roofing using rolled “soft” materials

When the roof is made from soft types of roofing, we are talking about roofing felt, ondulin, polymer (membrane) roofing. When deciding how to calculate the roof pitch, consider the following:

1. Number of covering layers. Depending on them, the angle of inclination of the roof structure can be from 2 to 15 degrees.
2. When covering in 2 layers, it would be good to stop at a roof angle of 15 degrees. For a three-layer one, it is enough to have a slope within 2-5 degrees.
3. Membrane coverings, which are optimal for any type of roof, including the most complex in its geometry, are placed on roofs that have a slope of 2-5 degrees.

Without a doubt, the angle of the roof will be chosen by the owner of the building. He must take into account that the roof is designed for temporary and permanent loads. Temporary include precipitation and its weight. These include wind, which puts pressure on the roof structure and the finishing coating itself. When constant loads are mentioned, we are talking about the weight of the roofing structure itself and the finishing coating material.

A structural element of the roof such as sheathing—its type, pitch, and design—depends on the slope of the roof. For example, the lower the angle of inclination, the shorter the pitch of the sheathing in the roofing system should be. The minimum roof slope requires a sheathing pitch of 35-45 centimeters.

One of the main questions is the amount of material for the finishing coating that needs to be calculated and purchased. The following trend can be seen here - a larger roof slope requires more material consumption.

I would like to offer some practical tips that will be useful when selecting roofing materials:

• with a slight roof slope (less than 10 degrees), the roof can be covered with a material containing stone chips or gravel (5 mm thick for chips and 15 mm for gravel).
• when the roof slope angle is more than 10 degrees, then a basic bitumen waterproofing device will be required. In case of use roll materials additional protection must be applied. This coating is usually a paint.
• covering the roof with roofing material such as corrugated board or asbestos cement sheets, provides sealing of butt seams. The joints in this case are made double.

We calculate the angle of inclination of the roof

Calculation of the roof slope angle depends on the height of the ridge. How high the roof at the ridge will be depends on the functional purpose of the attic space.

When a full-fledged attic space is made from the attic, the angle of inclination is calculated as follows:

For example, the end of the roof (the width of the pediment) is 6 meters. This figure is divided in half (6:2=3). The standard roof height at the ridge is always 1.8 meters.

Sin A=a/b=3/1.8=1.67

Using the Bradis table, an approximate value is found for the angle of inclination of the roof with a value of Sin A = 1.67 - this value is in the range of 58-59 degrees. You can stop at maximum value at 60 degrees, which will become our desired angle of inclination of the roof slope.

The construction of the roof is one of the important stages of construction. The roof protects the home and performs an aesthetic function, making the design of the building complete. Choice suitable material- not the only significant nuance. It is also necessary to correctly calculate the roof slope. This article will tell you how to do this.

Peculiarities

IN modern projects country mansions a large number of requirements are taken into account. Performers are forced not only to comply with standards, but also to implement the wishes and whims of customers. However, in the foreground are still regulatory requirements, because the roof, first of all, must be reliable. Therefore, architectural delights often fade into the background.

Roof covering must fulfill its intended purpose - to protect from moisture. In some cases, thermal and sound insulation is required. This may be necessary to increase the functionality of the premises under the roof. Therefore, designing a roof cannot be called a simple matter. This work requires extreme responsibility, especially if the customer insists on a complex configuration. In different situations, professionals use different techniques. Calculations are made using appropriate software.

The theory of calculations may also be of interest to the home owner. For example, such knowledge makes it possible to check whether the professionals used the correct methodology. They also help to correctly present your original ideas. In addition, the calculated parameters allow you to determine the required quantity building materials both for the rafter system and for the roofing.

The peculiarities of the calculations are that professionals use different quantities for measurements. For example, not everyone measures the slope angle in degrees. In the everyday life of some masters, there are such concepts as percentage ratio or relative aspect ratio. You also need to know what is considered the angle of the roof.

The angle of inclination of the roof is formed by the intersection of two parameters:

• one horizontal plane;
• one plane of the roof slope.

This parameter is measured from the top edge to the base of the rafter system. When making calculations, only acute angles are taken into account, since by definition there are no obtuse angles. Steep slopes are rare. Typically, they are used for decorative design(for example, when they build turrets in the Gothic style).

Attic roofs can be steep. In this case, the lower rafters are placed at a very large angle. On ordinary roofs, slopes up to 45 degrees are installed.

To get a better idea of ​​what it should look like, you can take a protractor and look at the degree divisions.

The value of the inclined angle is calculated as the ratio of the ridge parameters to half the width of the structure, multiplied by 100. Most professional builders use so-called tabular graphs. Depending on the indicators, roofs are usually divided into types.

Species

Experts distinguish several main types of roofs.

• Single pitch roof. In this case, the roof looks like a flat plane. It has distinctive height parameters.

• Gable roof. It is a reliable, easy-to-install option. The roof includes two slopes connected at right angles.

• Hip roof. It is equipped with four slopes, two of which are triangles, and two more are trapezoids. The top of such a roof looks cut off. Despite the complexity of the design, such roofs are very economical in terms of material consumption.

• Vaulted roof type. It is rare because it involves limited choice materials. Such options are built only from brick or stone. The rarity of choosing such roofs is also due to their heaviness. In small private construction this type is practically not used.

• Multi-gable roof type. It is complex in configuration, but very beautiful. Such a roof is difficult to lay due to the many junctions and lintels.

Experts also highlight types of roofing that can subsequently be used., and options that are not subject to exploitation. If professionals classify a roof as a non-exploitable type, this means that there is practically no space between the roof itself and the upper ceiling. This territory can be used, but only as a technical one. For example, this is the case with a low-slope pitched roof.

One pitched roofs most beneficial for construction. They require minimal costs for materials, and the work can be done independently. If the roof has a slight slope, then on its surface you can create a resting place without constructing a complex attic.

The space under the roof can be used if the roof type is pitched. The attic area can be used for household needs. It can also expand your living space.

The choice of one type of roof or another is associated with many nuances. One of the main ones is the climate factor.

Climate influence

For example, a huge load on a rafter structure can occur due to wind. Even a slight increase in the inclined angle increases the wind load. For example, if the roof slope angle is 30 degrees greater than the standard values, the wind load becomes five times greater. Therefore, even a slight increase in indicators can play a cruel joke on the owner of the house during a natural disaster.

Atmospheric precipitation has no less destructive effect on the quality of the roof. At the same time, a well-chosen slightly larger slope will avoid the accumulation of snow on the surface. There will be no snow melting at all if the roof slope is 30 degrees. And with a slope of 45 degrees, the standard indicators for snow load on the roof.

In northern countries (Sweden, Finland, Norway, etc.) it is customary to make very high pitched roofs. Obviously, snow does not stay on high slopes. However, it is generally accepted that some snow layer on the roof plays the role of additional thermal insulation.

To eliminate the risk of breaking the roofing material, a strong rafter system is installed, since a large weight will affect the entire structure.

It is worth remembering that the greater the inclined angle of the roof, the more money will have to be spent on construction. Costs are also associated with the choice of roof covering option (not all materials can be installed on high pitched roofs).

For different materials

Before choosing a roofing material, you should carefully consider technical features coverings. This will help you accept optimal solution and choose the most reliable option. There are rules that determine the relationship between the angle of the roof and the roofing structure used.

Slate covering or tiles can be laid on the roof with a minimum slope of 22 degrees. On roofs with a lower slope, moisture will accumulate and seep in at the joints of the parts. If the roof has slopes with a lower degree, you can use roofing felt and other bituminous materials that are mounted as a single piece.

Manufacturers of profiled sheets state that this material can be laid at a minimum permissible angle of 12 degrees. Moreover, if the slope angle is minimal, then the joints between the sheets must be sealed with sealant.

For metal tiles The minimum possible slope of the slope is 14 degrees. At the same time, there are rules for arranging floors. For example, if the angle is more than 45 degrees, then the installation location of the ridge board changes. The method of mounting the ridge itself also changes. For small values, an aeroroller is attached between the ridge strip and the tile. It prevents snow from penetrating under the roof.

For a roof covered with ondulin, the minimum possible slope is 6 degrees. For soft tiles the optimal surface slope is 11 degrees. Although for this material a greater slope is acceptable. In this case, the sheathing must be continuous.

Membrane-type coatings are more versatile. PVC membrane, EPDM membrane, TPO membrane are modern materials, suitable for roofs of any shape. The versatility of the materials is due to excellent technical characteristics and long service life.

When choosing a particular covering material, you should take into account not only the characteristics of the slopes, but also the strength values ​​of the roof. Structures must support not only their own weight, but also the weight of the roofing material. In addition, the entire roofing system must successfully withstand external loads.

The slope of the slopes is often associated not only with the choice of materials, but also with the choice of the type of sheathing. If the angle of the slope is small, then a continuous sheathing is installed. Also, when installing a flat roof, it is necessary to install a drainage system. There are regulatory parameters for any roofing options. They should be kept in mind even if the simplest flat option is chosen.

Standard values

Installing a flat roof is a simple undertaking. The main thing is to use properly selected high quality material. The slope of a flat roof is also important.

In reality, a flat roof is not completely horizontal. On such a roof, a slope of 15 degrees is constructed. Slopes must be present, since only in this case will water flow into the gutters. If the slope is not done in accordance with established standards, stagnant water will form on the roof surface.

When choosing one or another base, the type of structure should be taken into account. For example, if the floors are wooden, then additional weight for the roof is contraindicated.

Today you can find special slabs on sale that have high thermal insulation qualities. Such plates have a wedge shape. It is enough to lay the material on flat surface. The result is a slope that corresponds to standard indicators. The only drawback of the material is its fairly high cost.

When using other materials, you first need to make sure that the surface is absolutely flat. Then beacons are installed on it. The slope should be directed towards the drains.

When creating a ramp, it is worth considering the roof area. For a garage roof, for example, it is worth considering one slope, which will be directed into the drainage funnel. Bend for a standard house measuring 80 square meters. m will be 2-4 slopes. In this case, all of them must be sent to drainage system in order to freely deliver water to it.

How to calculate?

If there are usually no difficulties with the installation of a flat roof, then engineering calculations are required to install a roof with several slopes. The easiest way is to calculate and determine the values ​​in degrees. For example, to arrange a roof with a slope of 30 degrees, you can use a mathematical method.

This will require two measurements.

• Vertical height (H). The value is measured from the top point of the inclined plane to the bottom of the rafter system (from the ridge to the eaves).
• Laying (L). This is the horizontal length from the middle of the bottom point of the slope to the eaves.

Mathematical calculation is made according to the formula. You can calculate the required parameter as follows: I = H: L. For example, the laying length is 5 m, and the height is 3 m. In this case, the slope will be equal to 0.6 (when calculating I = 3: 5). This value must be multiplied by 100. It turns out 60 percent.

To convert the value into degrees, you can use a special table of ratios. It can be found in specialized textbooks. Sometimes such a table can be found on sale in construction hypermarkets. It is not necessary to convert relative values. With the values ​​​​from the example given, the angle of inclination will be equal to 30 degrees.

Experts do not always use a conversion table in their measurements. The coefficient in percentage can be used equally with the coefficient in degrees. In general, professionals use special tools in calculations. For example, you can measure the area parameter using a special inclinometer.

The tool is a ruler with a rack. One axis contains the usual scale in centimeters, the other - a pendulum. If the rack with divisions lies horizontally, then the pendulum will show zero. When measuring the slope, the rod is installed perpendicular to the ridge. In this case, the scale shows the result for a specific value immediately in degrees.

Currently, you can find a variety of tools on the market that can be used to measure slopes. The levels can be either drip-type devices or electronic devices. In this regard, the mathematical measurement method cannot be considered relevant. Modern instruments allow more accurate calculations.